Intumescent composition coated article

ABSTRACT

Coated articles of the invention are substrates coated with intumescent compositions which comprise certain nitrogencontaining aromatic sulfones, thiosulfonates, and sulfonates. Exemplary of the intumescent agents are bis(p-aminophenyl) sulfone, 1,2-bis (4-acetamidophenylsulfonyl)ethane, p,p&#39;&#39;diacetamidophenylthiosulfonate, and p,p&#39;&#39;-diaminophenylsulfonate.

States Patent 1 Elite 1 Oct. 30, 1973 INTUMESCENT COMPOSITION COATED ARTICLE [75] Inventor: Shirley H. Roth, Highland Park, NJ.

[22] Filed: Dec. 23, I971 [21] Appl. No.: 211,635

[52] 11.8. C1. 117/136, 106/15 FP, 252/81 [51} Int. Cl C09k 3/28 [58] Field of Search 117/136; 252/8.l;

106/15 FP; 260/3976, 453 R, 576

[56] References Cited UNITED STATES PATENTS 3,419,584 12/1968 Elslager et al. 260/397.6 2,385,899 10/1945 Weijlard 260/397.6 3,549,311 12/1970 Sting] 260/3976 3,145,226 8/1964 Ratz 260/453 R 3,663,464 5/1972 Sawko 106/15 FP OTHER PUBLlCATlONS l-leymann et a1. Derivatives of p.p-Diaminodipheny1 Sulfone II In J. Am. Chem. Soc. Vol. 67, 1945. p. 1987, 1990.

Primary Examinerwilliam D. Martin Assistant Examiner-Janyce A. Bell Attorney-Richard S. Strickler et al.

[57] ABSTRACT Coated articles of the invention are substrates coated with intumescent compositions which comprise certain nitrogen-containing aromatic sulfones, thiosulfonates, and sulfonates. Exemplary of the intumescent agents are bis(p-aminophenyl) sulfone, 1,2-bis (4- acetamidophenylsulfonyl)ethane, p,p'- diacetamidophenylthiosulfonate, and p,p'-diaminophenylsulfonate.

9 Claims, No Drawings INTUMESCENT COMPOSITION COATED ARTICLE BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to intumescent compositions and more particularly relates to such compositions containing a one-component intumescent agent.

2. Description of the Prior Art lt is known that a substrate may be protected from heat and fire by the application of an intumescent composition. Intumescent compositions of the prior art usually contain an intumescent agent having at least three components, i.e., a carbonific, a spumific, and a catalyst; and they are typically characterized by the disadvantages of high cost, low spreading rate, relatively poor efficiency, poor water resistance, and poor weatherability.

As disclosed in U. S. Pat. No. 3,535,130, it has already been discovered that a one-component intumescent agent has advantages over multicomponent intumescent agents. However, the intumescent agents of the patent have poor adherence to substrates and have an undesirable degree of moisture sensitivity.

SUMMARY OF THE INVENTION An object of this invention is to provide a novel class of one-component intumescent agents.

Another object is to provide such intumescent agents having good efficiency and a low level of moisture sensitivity.

These and other objects are attained by using as intumescent agents compounds corresponding to the formula:

wherein Ar is a divalent aromatic residue; R and R are hydrogen or a hydrocarbon, halohydrocarbon, or acyl radical; Z is in which R" is an alkylene radical containing lcarbon atoms, and n is 0 or 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The intumescent agents of the invention may be any compounds corresponding to the above formula. However, they are preferably compounds wherein Ar is a divalent aromatic residue derived from benzene or naphthalene or an alkyl, haloalkyl, alkoxy, haloalkoxy, halo, hydroxy, carboxy, amino, amido, or nitro derivative thereof. When the aromatic rings bear organic substituents, it is usually preferred that these substituents contain 1-5 carbon atoms. When there are halo substituents, it is usually preferred that they be chloro or bromo. It is also preferred that each of the aromatic rings have at least one free reactive position.

are bis(p-aminophenyl)sulfone, bis(4-amino-3- chlorophenyl)sulfone, bis(2-amino-4 bromophenyl)sulfone, bis(4-amino-2- ethylphenyl)sulfone, bis(3-amino-4-chloromethylphenyl)sulfone, bis(4-amino-2-butoxyphenyl)sulfone, bis(4-amino-3-chloromethoxyphenyl)sulfone, bis(4- amino-3 -carboxyphenyl )sulfone, bis( 3 ,4- diaminophenyl)sulfone, bis(4-amino-2- acetamidophenyl)sulfone, bis(2-am ino-4- nitrophenyl)sulfone, bis(4- methylaminophenyl)sulfone, bis( 4-chloroethylaminophenyl)sulfone, bis(4-bromomethylaminophenyl)sulfone, bis(4-phenylaminophenyl)sulfone, bis[4-(pchlorophenylamino)phenyl]sulfone, bisl4-(p-bromophenylamino)-phenyl]sulfone, bis(pacetamidophenyl)sulfone, bis(p-benzamidophenyl)sulfone, l,2-bis(4-acetamidophenylsulfonyl)ethane, and the corresponding naphthalene, thiosulfonate, and sulfonate compounds. The preferred intumescent agents include bis(p-aminophenyl)-sulfone, l ,2-bis( 4- acetamidophenylsulfonyl)ethane, p,p'- diacetamidophenylthiosulfonate, l ,2-bis(4-aminophenylsulfonyl)ethane, p,p'-diaminophenylthiosulfonate, p,p'-diacetamidophenylsulfonate, and p,p-diaminophenylsulfonate. When not readily available, these compounds may be prepared by known techniques.

For use in protecting a substrate from heat and fire, the intumescent agents of the invention may be applied in any suitable manner, e.g., electrodeposition, spraying of powdered intumescent agent onto an adhesive substrate, etc. However, it is usually preferred to compound the intumescent agent with a binder, e.g., nitrocellulose, and optionally also with one or more of the other ingredients conventionally used in intumescent compositions, e.g., stabilizers, dispersing agents, pigments, driers, biocides, anti-foamers, thickeners, protective colloids, fillers, blowing agents, etc.; disperse the composition in a suitable liquid medium, e.g., water or a solvent or solvent mixture; and apply the coating composition thus formed to the substrate to be protected. As is the case with conventional intumescent coating compositions, it is frequently convenient to apply these coating compositions in the form of a paint having a solids content of about 10-70 percent by weight and an intumescent agent/binder weight ratio of about 0.075-14/1 to deposit a coating having a dry thickness of about 0.00l-0.75 inch.

The intumescent agents of the invention are efficient, have low moisture sensitivity, and intumesce to form foams having good volume, cell structure, and adherence to substrates, such as wood, metal, and plastics. They are also useful as flame retardants in normally flammable compositions.

The following examples are given to illustrate the invention and are not intended as a limitation thereof.

EXAMPLE I Place one gram of bis(p-aminophenyl)sulfone in an aluminum pan and flame it with a propane torch. The

compound intumesces to form an excellent volume of foam having a good cell structure.

EXAMPLE ll ll RHNAr-fi-Z,.Ar-NHR wherein Ar is a divalent aromatic residue; R and R are hydrogen or a hydrocarbon, halohydrocarbon, or acyl radical; Z is in which R" is an alkylene radical containing 1-5 carbon atoms; and n is 0 or i.

2. The article of claim 1 wherein Ar is a divalent aromatic residue derived from benzene or naphthalene or an alkyl, haloalkyl, alkoxy, haloalkoxy, halo, hydroxy, carboxy, amino, amido, or nitro derivative thereof.

3. The article of claim 2 wherein Ar is a divalent aromatic residue derived from benzene.

4. The article of claim 1 wherein n is O.

5. The article of claim 4 wherein the intumescent agent is bis(p-aminophenyl)sulfone.

6. The article of claim 1 wherein i Z is R-]S|-.

7. The article of claim 6 wherein the intumescent agent is l,2-bis(4-acetamidophenylsulfonyl)-ethane.

8. The article of claim 1 wherein Z is 0 9. The article of claim 1 wherein Z is S 

2. The article of claim 1 wherein Ar is a divalent aromatic residue derived from benzene or naphthalene or an alkyl, haloalkyl, alkoxy, haloalkoxy, halo, hydroxy, carboxy, amino, amido, or nitro derivative thereof.
 3. The article of claim 2 wherein Ar is a divalent aromatic residue derived from benzene.
 4. The article of claim 1 wherein n is
 0. 5. The article of claim 4 wherein the intumescent agent is bis(p-aminophenyl)sulfone.
 6. The article of claim 1 wherein
 7. The article of claim 6 wherein the intumescent agent is 1,2-bis(4-acetamidophenylsulfonyl)-ethane.
 8. The article of claim 1 wherein Z is - 0 -.
 9. The article of claim 1 wherein Z is - S -. 